<html>
<head>
	<title></title>
	<script type="text/javascript">

	function a(){
		this.myvar = "my Object";
	}
	a.prototype.getInfo = function(){
		return "Old " + this.myvar;
	}

	</script>
</head>
<body>
<script type="text/javascript">
	var myObject = new a();
	var myObject2 = new a();
	console.debug(myObject.getInfo());
	console.debug(myObject2.getInfo());
	a.prototype.getInfo = function(){
		return "New " + this.myvar;
	}
	myObject.myvar = "oh my god";
	console.debug(myObject.getInfo());
	console.debug(myObject2.getInfo());
</script>
</body>
</html>